/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "uv.h"
#include "internal.h"

static int uv__dlerror(uv_lib_t* lib, int errorno);

int uv_dlopen(const char* filename, uv_lib_t* lib)
{
    WCHAR* filename_w = (WCHAR*)malloc(32768 * sizeof(WCHAR));

    lib->handle = NULL;
    lib->errmsg = NULL;

    if (!MultiByteToWideChar(CP_UTF8,
            0,
            filename,
            -1,
            filename_w,
            /*ARRAY_SIZE(filename_w)*/ 32768)) {
        return uv__dlerror(lib, GetLastError());
    }

    lib->handle = LoadLibraryExW(filename_w, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
    free(filename_w);
    if (lib->handle == NULL) {
        return uv__dlerror(lib, GetLastError());
    }

    return 0;
}

void uv_dlclose(uv_lib_t* lib)
{
    if (lib->errmsg) {
        LocalFree((void*)lib->errmsg);
        lib->errmsg = NULL;
    }

    if (lib->handle) {
        /* Ignore errors. No good way to signal them without leaking memory. */
        FreeLibrary(lib->handle);
        lib->handle = NULL;
    }
}

int uv_dlsym(uv_lib_t* lib, const char* name, void** ptr)
{
    *ptr = (void*)GetProcAddress(lib->handle, name);
    return uv__dlerror(lib, *ptr ? 0 : GetLastError());
}

const char* uv_dlerror(const uv_lib_t* lib)
{
    return lib->errmsg ? lib->errmsg : "no error";
}

static void uv__format_fallback_error(uv_lib_t* lib, int errorno)
{
    DWORD_PTR args[1] = { (DWORD_PTR)errorno };
    LPSTR fallback_error = "error: %1!d!";

    FormatMessageA(FORMAT_MESSAGE_FROM_STRING | FORMAT_MESSAGE_ARGUMENT_ARRAY | FORMAT_MESSAGE_ALLOCATE_BUFFER,
        fallback_error, 0, 0,
        (LPSTR)&lib->errmsg,
        0, (va_list*)args);
}

static int uv__dlerror(uv_lib_t* lib, int errorno)
{
    DWORD res;

    if (lib->errmsg) {
        LocalFree((void*)lib->errmsg);
        lib->errmsg = NULL;
    }

    if (errorno) {
        res = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, errorno,
            MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
            (LPSTR)&lib->errmsg, 0, NULL);
        if (!res && GetLastError() == ERROR_MUI_FILE_NOT_FOUND) {
            res = FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, errorno,
                0, (LPSTR)&lib->errmsg, 0, NULL);
        }

        if (!res) {
            uv__format_fallback_error(lib, errorno);
        }
    }

    return errorno ? -1 : 0;
}
